NM_000359.3:c.791G>A

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2PM5PP3_StrongPP5_Very_Strong

The NM_000359.3(TGM1):c.791G>A(p.Arg264Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,614,068 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R264W) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

TGM1
NM_000359.3 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 2.03

Variant links:

Genes affected

TGM1 (HGNC:11777): (transglutaminase 1) The protein encoded by this gene is a membrane protein that catalyzes the addition of an alkyl group from an akylamine to a glutamine residue of a protein, forming an alkylglutamine in the protein. This protein alkylation leads to crosslinking of proteins and catenation of polyamines to proteins. This gene contains either one or two copies of a 22 nt repeat unit in its 3' UTR. Mutations in this gene have been associated with autosomal recessive lamellar ichthyosis (LI) and nonbullous congenital ichthyosiform erythroderma (NCIE). [provided by RefSeq, Jul 2008]

TGM1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr14-24260026-G-A is described in Lovd as [Pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.984

PP5

Variant 14-24260025-C-T is Pathogenic according to our data. Variant chr14-24260025-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 312984.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr14-24260025-C-T is described in UniProt as null.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TGM1	NM_000359.3 link	c.791G>A	p.Arg264Gln	missense_variant	Exon 5 of 15	ENST00000206765.11	NP_000350.1	P22735-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
TGM1	ENST00000206765.11 link	c.791G>A	p.Arg264Gln	missense_variant	Exon 5 of 15	1	NM_000359.3	ENSP00000206765.6	P22735-1
TGM1	ENST00000559136.1 link	c.-137G>A		5_prime_UTR_variant	Exon 1 of 7	5		ENSP00000453337.1	H0YLT9
TGM1	ENST00000544573.5 link	c.-28-1637G>A		intron_variant	Intron 2 of 8	2		ENSP00000439446.1	P22735-2

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152204

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000578

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000278

AC:

AN:

251452

Hom.:

AF XY:

0.0000294

AC XY:

AN XY:

135918

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000980

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000157

AC:

AN:

1461864

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

727232

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000580

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000135

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152204

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74356

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000578

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000397

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.0000412

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Jan 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 264 of the TGM1 protein (p.Arg264Gln). This variant is present in population databases (rs781006633, gnomAD 0.02%). This missense change has been observed in individual(s) with congenital ichthyosis (PMID: 16968736, 30950025). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 312984). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TGM1 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects TGM1 function (PMID: 19212342). This variant disrupts the p.Arg264 amino acid residue in TGM1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 16968736, 27025581, 28403434). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Aug 12, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported with a second TGM1 variant, phase unknown, in a patient with congenital ichthyosis (PMID: 16968736); Published functional studies demonstrate diminished TGM1 enzyme activity (PMID: 19212342); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 34426522, 27025581, 34671977, 28403434, 30950025, 36262015, 19212342, 16968736) -

Lamellar ichthyosis

Pathogenic:1

Jul 27, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: TGM1 c.791G>A (p.Arg264Gln) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 251452 control chromosomes (gnomAD). c.791G>A has been reported in the literature as a compound heterozygous genotype in individuals affected with Lamellar Ichthyosis, including at least one case where it was confirmed to be in trans with a pathogenic variant (e.g. Oji_2006, Hu_2019). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function and found the variant results in <10% of normal activity and exhibits a slight improvement in activity at decreased temperatures (approximately 15% of WT at 31C) (Aufenvenne_2009). The following publications have been ascertained in the context of this evaluation (PMID: 19212342, 30950025, 16968736). Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. One submitter classified the variant as likely pathogenic, and one submitter classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Autosomal recessive congenital ichthyosis 1

Pathogenic:1

Feb 10, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.22

BayesDel_addAF

Pathogenic

0.26

BayesDel_noAF

Pathogenic

0.34

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.91

Eigen

Pathogenic

0.73

Eigen_PC

Uncertain

0.65

FATHMM_MKL

Uncertain

0.91

M_CAP

Uncertain

0.20

MetaRNN

Pathogenic

0.98

MetaSVM

Pathogenic

0.94

MutationAssessor

Pathogenic

3.4

PrimateAI

Uncertain

0.51

PROVEAN

Uncertain

-2.9

REVEL

Pathogenic

0.71

Sift

Uncertain

0.011

Sift4G

Uncertain

0.031

Polyphen

1.0

Vest4

0.89

MutPred

0.92

Gain of sheet (P = 0.1451);

MVP

0.97

MPC

0.93

ClinPred

0.94

GERP RS

5.4

Varity_R

0.30

gMVP

0.79

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over